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Ripin N, Macedo de Vasconcelos L, Ugay DA, Parker R. DDX6 modulates P-body and stress granule assembly, composition, and docking. J Cell Biol 2024; 223:e202306022. [PMID: 38536035 PMCID: PMC10978804 DOI: 10.1083/jcb.202306022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 12/20/2023] [Accepted: 03/04/2024] [Indexed: 04/01/2024] Open
Abstract
Stress granules and P-bodies are ribonucleoprotein (RNP) granules that accumulate during the stress response due to the condensation of untranslating mRNPs. Stress granules form in part by intermolecular RNA-RNA interactions and can be limited by components of the RNA chaperone network, which inhibits RNA-driven aggregation. Herein, we demonstrate that the DEAD-box helicase DDX6, a P-body component, can also limit the formation of stress granules, independent of the formation of P-bodies. In an ATPase, RNA-binding dependent manner, DDX6 limits the partitioning of itself and other RNPs into stress granules. When P-bodies are limited, proteins that normally partition between stress granules and P-bodies show increased accumulation within stress granules. Moreover, we show that loss of DDX6, 4E-T, and DCP1A increases P-body docking with stress granules, which depends on CNOT1 and PAT1B. Taken together, these observations identify a new role for DDX6 in limiting stress granules and demonstrate that P-body components can influence stress granule composition and docking with P-bodies.
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Affiliation(s)
- Nina Ripin
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | | | - Daniella A. Ugay
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | - Roy Parker
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
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2
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Wang JY, Liu YJ, Zhang XL, Liu YH, Jiang LL, Hu HY. PolyQ-expanded ataxin-2 aggregation impairs cellular processing-body homeostasis via sequestering the RNA helicase DDX6. J Biol Chem 2024:107413. [PMID: 38810698 DOI: 10.1016/j.jbc.2024.107413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 04/02/2024] [Accepted: 04/10/2024] [Indexed: 05/31/2024] Open
Abstract
Ataxin-2 (Atx2) is a polyglutamine (polyQ) tract-containing RNA-binding protein, while its polyQ expansion may cause protein aggregation that is implicated in the pathogenesis of neurodegenerative diseases such as spinocerebellar ataxia type 2 (SCA2). However, the molecular mechanism underlying how Atx2 aggregation contributes to the proteinopathies remains elusive. Here, we investigated the influence of Atx2 aggregation on the assembly and functionality of cellular processing bodies (P-bodies) by using biochemical and fluorescence imaging approaches. We have revealed that polyQ-expanded (PQE) Atx2 sequesters the DEAD-box RNA helicase (DDX6), an essential component of P-bodies, into aggregates or puncta via some RNA sequences. The N-terminal like-Sm (LSm) domain of Atx2 (residues 82-184) and the C-terminal helicase domain of DDX6 are responsible for the interaction and specific sequestration. Moreover, sequestration of DDX6 may aggravate pre-mRNA mis-splicing, and interfere with the assembly of cellular P-bodies, releasing the endoribonuclease MARF1 that promotes mRNA decay and translational repression. Rescuing the DDX6 protein level can recover the assembly and functionality of P-bodies preventing targeted mRNA from degradation. This study provides a line of evidence for sequestration of the P-body components and impairment of the P-body homeostasis in dysregulating RNA metabolism, which is implicated in the disease pathologies and a potential therapeutic target.
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Affiliation(s)
- Jian-Yang Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, P. R. China; University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Ya-Jun Liu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, P. R. China; University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xiang-Le Zhang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, P. R. China; University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yin-Hu Liu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, P. R. China; University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Lei-Lei Jiang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, P. R. China
| | - Hong-Yu Hu
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, P. R. China.
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3
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Shelkovnikova TA, Hautbergue GM. RNP granules in ALS and neurodegeneration: From multifunctional membraneless organelles to therapeutic opportunities. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2024; 176:455-479. [PMID: 38802180 DOI: 10.1016/bs.irn.2024.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Amyotrophic lateral sclerosis (ALS) and related neurodegenerative diseases are characterised by dysfunction of a host of RNA-binding proteins (RBPs) and a severely disrupted RNA metabolism. Recently, RBP-harbouring phase-separated complexes, ribonucleoprotein (RNP) granules, have come into the limelight as "crucibles" of neuronal pathology in ALS. RNP granules are indispensable for the multitude of regulatory processes underlying cellular RNA metabolism and serve as critical organisers of cellular biochemistry. Neurons, highly specialised cells, heavily rely on RNP granules for efficient trafficking, signalling and stress responses. Multiple RNP granule components, primarily RBPs such as TDP-43 and FUS, are affected by ALS mutations. However, even in the absence of mutations, RBP proteinopathies represent pathophysiological hallmarks of ALS. Given the high local concentrations of RBPs and RNAs, their weakened or enhanced interactions within RNP granules disrupt their homeostasis. Thus, the physiological process of phase separation and RNP granule formation, vital for maintaining the high-functioning state of neuronal cells, becomes their Achilles heel. Here, we will review the recent literature on the causes and consequences of abnormal RNP granule functioning in ALS and related disorders. In particular, we will summarise the evidence for the network-level dysfunction of RNP granules in these conditions and discuss considerations for therapeutic interventions to target RBPs, RNP granules and their network as a whole.
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Affiliation(s)
- Tatyana A Shelkovnikova
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom; Neuroscience Institute, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom.
| | - Guillaume M Hautbergue
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom; Neuroscience Institute, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom; Healthy Lifespan Institute (HELSI), University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom.
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4
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Koizumi T, Fujimoto A, Kawaguchi H, Kurosaki T, Kitamura A. Stress Granule Dysfunction via Chromophore-Associated Light Inactivation. ACS OMEGA 2024; 9:21298-21306. [PMID: 38764671 PMCID: PMC11097178 DOI: 10.1021/acsomega.4c01469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 04/17/2024] [Accepted: 04/23/2024] [Indexed: 05/21/2024]
Abstract
Stress granules (SGs) are cytoplasmic condensates composed of various proteins and RNAs that protect translation-associated machinery from harmful conditions during stress. However, the method of spatiotemporal inactivation of condensates such as SGs in live cells to study cellular phenotypes is still in the process of being demonstrated. Here, we show that the inactivation of SGs by chromophore-associated light inactivation (CALI) using a genetically encoded red fluorescence protein (SuperNova-Red) as a photosensitizer leads to differences in cell viability during recovery from hyperosmotic stress. CALI delayed the disassembly kinetics of SGs during recovery from hyperosmotic stress. Consequently, CALI could inactivate the SGs, and the cellular fate due to SGs could be analyzed. Furthermore, CALI is an effective spatiotemporal knockdown method for intracellular condensates/aggregates and would contribute to the elucidation of importance of such condensates/aggregates.
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Affiliation(s)
- Takumi Koizumi
- Laboratory
of Cellular and Molecular Sciences, Graduate School of Life Science, Hokkaido University, Sapporo 001-0021, Japan
| | - Ai Fujimoto
- Laboratory
of Cellular and Molecular Sciences, Graduate School of Life Science, Hokkaido University, Sapporo 001-0021, Japan
| | - Haruka Kawaguchi
- Laboratory
of Cellular and Molecular Sciences, Graduate School of Life Science, Hokkaido University, Sapporo 001-0021, Japan
| | - Tsumugi Kurosaki
- Laboratory
of Cellular and Molecular Sciences, Graduate School of Life Science, Hokkaido University, Sapporo 001-0021, Japan
| | - Akira Kitamura
- Laboratory
of Cellular and Molecular Sciences, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan
- PRIME, Japan
Agency for Medical Research and Development, Chiyoda-ku, Tokyo 100-004, Japan
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5
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Chen RX, Xu SD, Deng MH, Hao SH, Chen JW, Ma XD, Zhuang WT, Cao JH, Lv YR, Lin JL, Li SY, Qiao GB, Xie D, Wang FW. Mex-3 RNA binding family member A (MEX3A)/circMPP6 complex promotes colorectal cancer progression by inhibiting autophagy. Signal Transduct Target Ther 2024; 9:80. [PMID: 38565536 PMCID: PMC10987644 DOI: 10.1038/s41392-024-01787-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 01/30/2024] [Accepted: 03/01/2024] [Indexed: 04/04/2024] Open
Abstract
RNA-binding proteins (RBPs)-RNA networks have contributed to cancer development. Circular RNAs (circRNAs) are considered as protein recruiters; nevertheless, the patterns of circRNA-protein interactions in colorectal cancer (CRC) are still lacking. Processing bodies (PBs) formed through liquid-liquid phase separation (LLPS) are membrane-less organelles (MLOs) consisting of RBPs and RNA. Previous evidence suggests a connection between PBs dynamics and cancer progression. Despite the increasingly acknowledged crucial role of RBPs and RNA in the accumulation and maintenance of MLOs, there remains a lack of specific research on the interactions between PBs-related RBPs and circRNAs in CRC. Herein, we identify that MEX-3 RNA binding family member A (MEX3A), frequently upregulated in CRC tissues, predicts poorer patient survival. Elevated MEX3A accelerates malignance and inhibits autophagy of CRC cells. Importantly, MEX3A undergoes intrinsically disordered regions (IDRs)-dependent LLPS in the cytoplasm. Specifically, circMPP6 acts as a scaffold to facilitate the interaction between MEX3A and PBs proteins. The MEX3A/circMPP6 complex modulates PBs dynamic and promotes UPF-mediated phosphodiesterase 5A (PDE5A) mRNA degradation, consequently leading to the aggressive properties of CRC cells. Clinically, CRC patients exhibiting high MEX3A expression and low PDE5A expression have the poorest overall survival. Our findings reveal a collaboration between MEX3A and circMPP6 in the regulation of mRNA decay through triggering the PBs aggregation, which provides prognostic markers and/or therapeutic targets for CRC.
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Affiliation(s)
- Ri-Xin Chen
- Department of Thoracic Surgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, 510080, China
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
- Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, 510080, China
| | - Shui-Dan Xu
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
| | - Min-Hua Deng
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
| | - Shi-Hui Hao
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
| | - Jie-Wei Chen
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
- Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
| | - Xiao-Dan Ma
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
| | - Wei-Tao Zhuang
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
| | - Jing-Hua Cao
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
| | - Yong-Rui Lv
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
| | - Jin-Long Lin
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
| | - Si-Yu Li
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
| | - Gui-Bin Qiao
- Department of Thoracic Surgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, 510080, China.
| | - Dan Xie
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China.
- Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China.
| | - Feng-Wei Wang
- State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China.
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6
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Nicchitta CV. An emerging role for the endoplasmic reticulum in stress granule biogenesis. Semin Cell Dev Biol 2024; 156:160-166. [PMID: 36202692 PMCID: PMC10208384 DOI: 10.1016/j.semcdb.2022.09.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 09/07/2022] [Accepted: 09/26/2022] [Indexed: 11/07/2022]
Abstract
Stress granules (SGs), structurally dynamic, optically resolvable, macromolecular assemblies of mRNAs, RNA binding proteins (RBPs), translation factors, ribosomal subunits, as well as other interacting proteins, assemble in response to cell stress conditions that elicit phosphorylation of eukaryotic initiation factor 2α (eIF2α) and consequently, the inactivation of translation initiation. SG biology is conserved throughout eukaryotes and has recently been linked to the pathological sequelae of neurodegenerative disorders, cancer biology, and viral infection. Substantial insights into mechanisms of SG biogenesis, and more broadly the phenomenon of biological liquid-liquid phase separation (LLPS), have been aided by detailed proteomic and transcriptomic studies as well as in vitro reconstitution approaches. A particularly interesting and largely unexplored element of SG biology is the cell biological context of SG biogenesis, including its subcellular organization and more recently, evidence that the endoplasmic reticulum (ER) membrane may serve important functions in RNA granule biology generally and SG biogenesis specifically. A central role for the ER in SG biogenesis is discussed and a hypothesis linking SG formation on the ER to the trafficking, localization and de novo translation of newly exported mRNAs is presented.
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7
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Mori F, Yasui H, Miki Y, Kon T, Arai A, Kurotaki H, Tomiyama M, Wakabayashi K. Colocalization of TDP-43 and stress granules at the early stage of TDP-43 aggregation in amyotrophic lateral sclerosis. Brain Pathol 2024; 34:e13215. [PMID: 37793650 PMCID: PMC10901621 DOI: 10.1111/bpa.13215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 09/20/2023] [Indexed: 10/06/2023] Open
Abstract
TDP-43 aggregates (skeins and round inclusions [RIs]) are frequent histopathological features of amyotrophic lateral sclerosis (ALS). We have shown that diffuse punctate cytoplasmic staining (DPCS) is the earliest pathologic manifestation of TDP-43 in ALS, corresponding to nonfibrillar TDP-43 located in the rough endoplasmic reticulum. Previous in vitro studies have suggested that TDP-43 inclusions may be derived from stress granules (SGs). Therefore, we investigated the involvement of SGs in the formation of TDP-43 inclusions. Formalin-fixed spinal cords of six ALS patients with a disease duration of less than 1 year (short duration), eight patients with a disease duration of 2-5 years (standard duration), and five normal controls were subjected to histopathological examination using antibodies against an SG marker, HuR. In normal controls, the cytoplasm of anterior horn cells was diffusely HuR-positive. In short-duration and standard-duration ALS, the number of HuR-positive anterior horn cells was significantly decreased relative to the controls. DPCS and RIs were more frequent in short-duration ALS than in standard-duration ALS. The majority of DPCS areas and a small proportion of RIs, but not skeins, were positive for HuR. Immunoelectron microscopy showed that ribosome-like granular structures in DPCS areas and RIs were labeled with anti-HuR, whereas skeins were not. These findings suggest that colocalization of TDP-43 and SGs occurs at the early stage of TDP-43 aggregation.
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Affiliation(s)
- Fumiaki Mori
- Department of NeuropathologyInstitute of Brain Science, Hirosaki University Graduate School of MedicineHirosakiJapan
| | - Hina Yasui
- Department of NeuropathologyInstitute of Brain Science, Hirosaki University Graduate School of MedicineHirosakiJapan
| | - Yasuo Miki
- Department of NeuropathologyInstitute of Brain Science, Hirosaki University Graduate School of MedicineHirosakiJapan
| | - Tomoya Kon
- Department of NeurologyInstitute of Brain Science, Hirosaki University Graduate School of MedicineHirosakiJapan
| | - Akira Arai
- Department of NeurologyAomori Prefectural Central HospitalAomoriJapan
| | | | - Masahiko Tomiyama
- Department of NeurologyInstitute of Brain Science, Hirosaki University Graduate School of MedicineHirosakiJapan
| | - Koichi Wakabayashi
- Department of NeuropathologyInstitute of Brain Science, Hirosaki University Graduate School of MedicineHirosakiJapan
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8
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Robinson AO, Lee J, Cameron A, Keating CD, Adamala KP. Cell-Free Expressed Membraneless Organelles Inhibit Translation in Synthetic Cells. ACS Biomater Sci Eng 2024; 10:773-781. [PMID: 38226971 DOI: 10.1021/acsbiomaterials.3c01052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
Compartments within living cells create specialized microenvironments, allowing multiple reactions to be carried out simultaneously and efficiently. While some organelles are bound by a lipid bilayer, others are formed by liquid-liquid phase separation such as P-granules and nucleoli. Synthetic minimal cells are widely used to study many natural processes, including organelle formation. In this work, synthetic cells expressing artificial membrane-less organelles that inhibit translation are described. RGG-GFP-RGG, a phase-separating protein derived from Caenorhabditis elegans P-granules, is expressed by cell-free transcription and translation, forming artificial membraneless organelles that can sequester RNA and reduce protein expression in synthetic cells. The introduction of artificial membrane-less organelles creates complex microenvironments within the synthetic cell cytoplasm and functions as a tool to inhibit protein expression in synthetic cells. The engineering of compartments within synthetic cells furthers the understanding of the evolution and function of natural organelles and facilitates the creation of more complex and multifaceted synthetic lifelike systems.
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Affiliation(s)
- Abbey O Robinson
- Department of Genetics, Cell Biology and Development, University of Minnesota, 420 SE Washington Ave., Minneapolis, Minnesota 55455, United States
| | - Jessica Lee
- Department of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802, United States
| | - Anders Cameron
- Department of Genetics, Cell Biology and Development, University of Minnesota, 420 SE Washington Ave., Minneapolis, Minnesota 55455, United States
| | - Christine D Keating
- Department of Chemistry, The Pennsylvania State University, 104 Chemistry Building, University Park, Pennsylvania 16802, United States
| | - Katarzyna P Adamala
- Department of Genetics, Cell Biology and Development, University of Minnesota, 420 SE Washington Ave., Minneapolis, Minnesota 55455, United States
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9
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Kim J, Qin S, Zhou HX, Rosen MK. Surface Charge Can Modulate Phase Separation of Multidomain Proteins. J Am Chem Soc 2024; 146:3383-3395. [PMID: 38262618 PMCID: PMC10859935 DOI: 10.1021/jacs.3c12789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 12/28/2023] [Accepted: 12/29/2023] [Indexed: 01/25/2024]
Abstract
Phase separation has emerged as an important mechanism explaining the formation of certain biomolecular condensates. Biological phase separation is often driven by the multivalent interactions of modular protein domains. Beyond valency, the physical features of folded domains that promote phase separation are poorly understood. We used a model system─the small ubiquitin modifier (SUMO) and its peptide ligand, the SUMO interaction motif (SIM)─to examine how domain surface charge influences multivalency-driven phase separation. Phase separation of polySUMO and polySIM was altered by pH via a change in the protonation state of SUMO surface histidines. These effects were recapitulated by histidine mutations, which modulated SUMO solubility and polySUMO-polySIM phase separation in parallel and were quantitatively explained by atomistic modeling of weak interactions among proteins in the system. Thus, surface charge can tune the phase separation of multivalent proteins, suggesting a means of controlling phase separation biologically, evolutionarily, and therapeutically.
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Affiliation(s)
- Jonggul Kim
- Department
of Biophysics, University of Texas Southwestern
Medical Center, Dallas, Texas 75390, United States
- Howard
Hughes Medical Institute, Dallas, Texas 75390, United States
| | - Sanbo Qin
- Department
of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, United States
| | - Huan-Xiang Zhou
- Department
of Chemistry, University of Illinois Chicago, Chicago, Illinois 60607, United States
- Department
of Physics, University of Illinois Chicago, Chicago, Illinois 60607, United States
| | - Michael K. Rosen
- Department
of Biophysics, University of Texas Southwestern
Medical Center, Dallas, Texas 75390, United States
- Howard
Hughes Medical Institute, Dallas, Texas 75390, United States
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10
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Louati S, Wozny AS, Malesys C, Daguenet E, Ladjohounlou R, Alphonse G, Tomasetto C, Magné N, Rodriguez-Lafrasse C. Differential Formation of Stress Granules in Radiosensitive and Radioresistant Head and Neck Squamous Cell Carcinoma Cells. Int J Radiat Oncol Biol Phys 2024; 118:485-497. [PMID: 37619790 DOI: 10.1016/j.ijrobp.2023.08.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 08/02/2023] [Accepted: 08/11/2023] [Indexed: 08/26/2023]
Abstract
PURPOSE Stress granules (SGs) are cytoplasmic aggregates in which mRNAs and specific proteins are trapped in response to a variety of damaging agents. They participate in the cellular defense mechanisms. Currently, their mechanism of formation in response to ionizing radiation and their role in tumor-cell radiosensitivity remain elusive. METHODS AND MATERIALS The kinetics of SG formation was investigated after the delivery of photon irradiation at different doses to head and neck squamous cell carcinoma cell lines with different radiosensitivities and the HeLa cervical cancer cell line (used as reference). In parallel, the response to a canonical inducer of SGs, sodium arsenite, was also studied. Immunolabeling of SG-specific proteins and mRNA fluorescence in situ hybridization enabled SG detection and quantification. Furthermore, a ribopuromycylation assay was used to assess the cell translational status. To determine whether reactive oxygen species were involved in SG formation, their scavenging or production was induced by pharmacologic pretreatment in both SCC61 and SQ20B cells. RESULTS Photon irradiation at different doses led to the formation of cytoplasmic foci that were positive for different SG markers. The presence of SGs gradually increased from 30 minutes to 2 hours postexposure in HeLa, SCC61, and Cal60 radiosensitive cells. In turn, the SQ20B and FaDu radioresistant cells did not form SGs. These results indicated a correlation between sensitivity to photon irradiation and SG formation. Moreover, SG formation was significantly reduced by reactive oxygen species scavenging using dimethyl sulfoxide in SCC61 cells, which supported their role in SG formation. However, a reciprocal experiment in SQ20B cells that depleted glutathione using buthionine sulfoximide did not restore SG formation in these cells. CONCLUSIONS SGs are formed in response to irradiation in radiosensitive, but not in radioresistant, head and neck squamous cell carcinoma cells. Interestingly, compared with sodium arsenite-induced SGs, photon-induced SGs exhibited a different morphology and cellular localization. Moreover, photon-induced SGs were not associated with the inhibition of translation; rather, they depended on oxidative stress.
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Affiliation(s)
- Safa Louati
- Cellular and Molecular Radiobiology Laboratory, Lyon-Sud Medical School, UMR CNRS 5822/IP2I, Université de Lyon, Lyon 1 University, Oullins, France; Department of Research and Teaching in Oncology, Hôpital Nord, Saint-Priest en Jarez, France
| | - Anne-Sophie Wozny
- Cellular and Molecular Radiobiology Laboratory, Lyon-Sud Medical School, UMR CNRS 5822/IP2I, Université de Lyon, Lyon 1 University, Oullins, France; Department of Biochemistry and Molecular Biology, Lyon-Sud Hospital, Hospices Civils de Lyon, Pierre-Bénite, France
| | - Céline Malesys
- Cellular and Molecular Radiobiology Laboratory, Lyon-Sud Medical School, UMR CNRS 5822/IP2I, Université de Lyon, Lyon 1 University, Oullins, France
| | - Elisabeth Daguenet
- Department of Research and Teaching in Oncology, Hôpital Nord, Saint-Priest en Jarez, France
| | - Riad Ladjohounlou
- Cellular and Molecular Radiobiology Laboratory, Lyon-Sud Medical School, UMR CNRS 5822/IP2I, Université de Lyon, Lyon 1 University, Oullins, France
| | - Gersende Alphonse
- Cellular and Molecular Radiobiology Laboratory, Lyon-Sud Medical School, UMR CNRS 5822/IP2I, Université de Lyon, Lyon 1 University, Oullins, France; Department of Biochemistry and Molecular Biology, Lyon-Sud Hospital, Hospices Civils de Lyon, Pierre-Bénite, France
| | - Catherine Tomasetto
- Institute of Genetic, Molecular and Cellular Biology, Université de Strasbourg, Illkirch, France
| | - Nicolas Magné
- Cellular and Molecular Radiobiology Laboratory, Lyon-Sud Medical School, UMR CNRS 5822/IP2I, Université de Lyon, Lyon 1 University, Oullins, France; Radiotherapy Department, Bergonié Institute, Bordeaux, France
| | - Claire Rodriguez-Lafrasse
- Cellular and Molecular Radiobiology Laboratory, Lyon-Sud Medical School, UMR CNRS 5822/IP2I, Université de Lyon, Lyon 1 University, Oullins, France; Department of Biochemistry and Molecular Biology, Lyon-Sud Hospital, Hospices Civils de Lyon, Pierre-Bénite, France.
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11
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Turan G, Olgun ÇE, Ayten H, Toker P, Ashyralyyev A, Savaş B, Karaca E, Muyan M. Dynamic proximity interaction profiling suggests that YPEL2 is involved in cellular stress surveillance. Protein Sci 2024; 33:e4859. [PMID: 38145972 PMCID: PMC10804680 DOI: 10.1002/pro.4859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 11/30/2023] [Accepted: 12/03/2023] [Indexed: 12/27/2023]
Abstract
YPEL2 is a member of the evolutionarily conserved YPEL family involved in cellular proliferation, mobility, differentiation, senescence, and death. However, the mechanism by which YPEL2, or YPEL proteins, mediates its effects is largely unknown. Proteins perform their functions in a network of proteins whose identities, amounts, and compositions change spatiotemporally in a lineage-specific manner in response to internal and external stimuli. Here, we explored interaction partners of YPEL2 by using dynamic TurboID-coupled mass spectrometry analyses to infer a function for the protein. Our results using inducible transgene expressions in COS7 cells indicate that proximity interaction partners of YPEL2 are mainly involved in RNA and mRNA metabolic processes, ribonucleoprotein complex biogenesis, regulation of gene silencing by miRNA, and cellular responses to stress. We showed that YPEL2 interacts with the RNA-binding protein ELAVL1 and the selective autophagy receptor SQSTM1. We also found that YPEL2 localizes stress granules in response to sodium arsenite, an oxidative stress inducer, which suggests that YPEL2 participates in stress granule-related processes. Establishing a point of departure in the delineation of structural/functional features of YPEL2, our results suggest that YPEL2 may be involved in stress surveillance mechanisms.
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Affiliation(s)
- Gizem Turan
- Department of Biological SciencesMiddle East Technical UniversityAnkaraTürkiye
| | - Çağla Ece Olgun
- Department of Biological SciencesMiddle East Technical UniversityAnkaraTürkiye
| | - Hazal Ayten
- Department of Biological SciencesMiddle East Technical UniversityAnkaraTürkiye
| | - Pelin Toker
- Department of Biological SciencesMiddle East Technical UniversityAnkaraTürkiye
| | | | - Büşra Savaş
- İzmir Biomedicine and Genome CenterİzmirTürkiye
- Izmir International Biomedicine and Genome InstituteDokuz Eylül UniversityIzmirTürkiye
| | - Ezgi Karaca
- İzmir Biomedicine and Genome CenterİzmirTürkiye
- Izmir International Biomedicine and Genome InstituteDokuz Eylül UniversityIzmirTürkiye
| | - Mesut Muyan
- Department of Biological SciencesMiddle East Technical UniversityAnkaraTürkiye
- CanSyl LaboratoriesMiddle East Technical UniversityAnkaraTürkiye
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12
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Wadsworth GM, Zahurancik WJ, Zeng X, Pullara P, Lai LB, Sidharthan V, Pappu RV, Gopalan V, Banerjee PR. RNAs undergo phase transitions with lower critical solution temperatures. Nat Chem 2023; 15:1693-1704. [PMID: 37932412 PMCID: PMC10872781 DOI: 10.1038/s41557-023-01353-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 09/19/2023] [Indexed: 11/08/2023]
Abstract
Co-phase separation of RNAs and RNA-binding proteins drives the biogenesis of ribonucleoprotein granules. RNAs can also undergo phase transitions in the absence of proteins. However, the physicochemical driving forces of protein-free, RNA-driven phase transitions remain unclear. Here we report that various types of RNA undergo phase separation with system-specific lower critical solution temperatures. This entropically driven phase separation is an intrinsic feature of the phosphate backbone that requires Mg2+ ions and is modulated by RNA bases. RNA-only condensates can additionally undergo enthalpically favourable percolation transitions within dense phases. This is enabled by a combination of Mg2+-dependent bridging interactions between phosphate groups and RNA-specific base stacking and base pairing. Phase separation coupled to percolation can cause dynamic arrest of RNAs within condensates and suppress the catalytic activity of an RNase P ribozyme. Our work highlights the need to incorporate RNA-driven phase transitions into models for ribonucleoprotein granule biogenesis.
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Affiliation(s)
- Gable M Wadsworth
- Department of Physics, The State University of New York at Buffalo, Buffalo, NY, USA
| | - Walter J Zahurancik
- Department of Chemistry and Biochemistry, Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Xiangze Zeng
- Department of Biomedical Engineering and Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO, USA
- Department of Physics, Hong Kong Baptist University, Hong Kong, China
- Teaching and Research Division, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China
| | - Paul Pullara
- Department of Physics, The State University of New York at Buffalo, Buffalo, NY, USA
| | - Lien B Lai
- Department of Chemistry and Biochemistry, Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Vaishnavi Sidharthan
- Department of Chemistry and Biochemistry, Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Rohit V Pappu
- Department of Biomedical Engineering and Center for Biomolecular Condensates, Washington University in St. Louis, St. Louis, MO, USA.
| | - Venkat Gopalan
- Department of Chemistry and Biochemistry, Center for RNA Biology, The Ohio State University, Columbus, OH, USA.
| | - Priya R Banerjee
- Department of Physics, The State University of New York at Buffalo, Buffalo, NY, USA.
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13
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Gao G, Sumrall ES, Pitchiaya S, Bitzer M, Alberti S, Walter NG. Biomolecular condensates in kidney physiology and disease. Nat Rev Nephrol 2023; 19:756-770. [PMID: 37752323 DOI: 10.1038/s41581-023-00767-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2023] [Indexed: 09/28/2023]
Abstract
The regulation and preservation of distinct intracellular and extracellular solute microenvironments is crucial for the maintenance of cellular homeostasis. In mammals, the kidneys control bodily salt and water homeostasis. Specifically, the urine-concentrating mechanism within the renal medulla causes fluctuations in extracellular osmolarity, which enables cells of the kidney to either conserve or eliminate water and electrolytes, depending on the balance between intake and loss. However, relatively little is known about the subcellular and molecular changes caused by such osmotic stresses. Advances have shown that many cells, including those of the kidney, rapidly (within seconds) and reversibly (within minutes) assemble membraneless, nano-to-microscale subcellular assemblies termed biomolecular condensates via the biophysical process of hyperosmotic phase separation (HOPS). Mechanistically, osmotic cell compression mediates changes in intracellular hydration, concentration and molecular crowding, rendering HOPS one of many related phase-separation phenomena. Osmotic stress causes numerous homo-multimeric proteins to condense, thereby affecting gene expression and cell survival. HOPS rapidly regulates specific cellular biochemical processes before appropriate protective or corrective action by broader stress response mechanisms can be initiated. Here, we broadly survey emerging evidence for, and the impact of, biomolecular condensates in nephrology, where initial concentration buffering by HOPS and its subsequent cellular escalation mechanisms are expected to have important implications for kidney physiology and disease.
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Affiliation(s)
- Guoming Gao
- Biophysics Graduate Program, University of Michigan, Ann Arbor, MI, USA
- Department of Chemistry and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI, USA
| | - Emily S Sumrall
- Biophysics Graduate Program, University of Michigan, Ann Arbor, MI, USA
- Department of Chemistry and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI, USA
| | | | - Markus Bitzer
- Department of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Simon Alberti
- Technische Universität Dresden, Biotechnology Center (BIOTEC) and Center for Molecular and Cellular Engineering (CMCB), Dresden, Germany
| | - Nils G Walter
- Department of Chemistry and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI, USA.
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14
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Bohnsack KE, Yi S, Venus S, Jankowsky E, Bohnsack MT. Cellular functions of eukaryotic RNA helicases and their links to human diseases. Nat Rev Mol Cell Biol 2023; 24:749-769. [PMID: 37474727 DOI: 10.1038/s41580-023-00628-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2023] [Indexed: 07/22/2023]
Abstract
RNA helicases are highly conserved proteins that use nucleoside triphosphates to bind or remodel RNA, RNA-protein complexes or both. RNA helicases are classified into the DEAD-box, DEAH/RHA, Ski2-like, Upf1-like and RIG-I families, and are the largest class of enzymes active in eukaryotic RNA metabolism - virtually all aspects of gene expression and its regulation involve RNA helicases. Mutation and dysregulation of these enzymes have been linked to a multitude of diseases, including cancer and neurological disorders. In this Review, we discuss the regulation and functional mechanisms of RNA helicases and their roles in eukaryotic RNA metabolism, including in transcription regulation, pre-mRNA splicing, ribosome assembly, translation and RNA decay. We highlight intriguing models that link helicase structure, mechanisms of function (such as local strand unwinding, translocation, winching, RNA clamping and displacing RNA-binding proteins) and biological roles, including emerging connections between RNA helicases and cellular condensates formed through liquid-liquid phase separation. We also discuss associations of RNA helicases with human diseases and recent efforts towards the design of small-molecule inhibitors of these pivotal regulators of eukaryotic gene expression.
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Affiliation(s)
- Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany.
| | - Soon Yi
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Sarah Venus
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Eckhard Jankowsky
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Moderna, Cambridge, MA, USA.
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany.
- Göttingen Centre for Molecular Biosciences, University of Göttingen, Göttingen, Germany.
- Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
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15
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Borodavka A, Acker J. Seeing Biomolecular Condensates Through the Lens of Viruses. Annu Rev Virol 2023; 10:163-182. [PMID: 37040799 DOI: 10.1146/annurev-virology-111821-103226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Phase separation of viral biopolymers is a key factor in the formation of cytoplasmic viral inclusions, known as sites of virus replication and assembly. This review describes the mechanisms and factors that affect phase separation in viral replication and identifies potential areas for future research. Drawing inspiration from studies on cellular RNA-rich condensates, we compare the hierarchical coassembly of ribosomal RNAs and proteins in the nucleolus to the coordinated coassembly of viral RNAs and proteins taking place within viral factories in viruses containing segmented RNA genomes. We highlight the common characteristics of biomolecular condensates in viral replication and how this new understanding is reshaping our views of virus assembly mechanisms. Such studies have the potential to uncover unexplored antiviral strategies targeting these phase-separated states.
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Affiliation(s)
- Alexander Borodavka
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom;
| | - Julia Acker
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom;
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16
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Falzarano MS, Mietto M, Fortunato F, Farnè M, Martini F, Ala P, Selvatici R, Muntoni F, Ferlini A. mRNA in situ hybridization exhibits unbalanced nuclear/cytoplasmic dystrophin transcript repartition in Duchenne myogenic cells and skeletal muscle biopsies. Sci Rep 2023; 13:15942. [PMID: 37743371 PMCID: PMC10518324 DOI: 10.1038/s41598-023-43134-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 09/20/2023] [Indexed: 09/26/2023] Open
Abstract
To gain insight on dystrophin (DMD) gene transcription dynamics and spatial localization, we assayed the DMD mRNA amount and defined its compartmentalization in myoblasts, myotubes, and skeletal muscle biopsies of Duchenne muscular dystrophy (DMD) patients. Using droplet digital PCR, Real-time PCR, and RNAscope in situ hybridization, we showed that the DMD transcript amount is extremely reduced in both DMD patients' cells and muscle biopsies and that mutation-related differences occur. We also found that, compared to controls, DMD transcript is dramatically reduced in the cytoplasm, as up to 90% of it is localized in nuclei, preferentially at the perinuclear region. Using RNA/protein colocalization experiments, we showed that about 40% of nuclear DMD mRNA is localized in the nucleoli in both control and DMD myogenic cells. Our results clearly show that mutant DMD mRNA quantity is strongly reduced in the patients' myogenic cells and muscle biopsies. Furthermore, mutant DMD mRNA compartmentalization is spatially unbalanced due to a shift in its localization towards the nuclei. This abnormal transcript repartition contributes to the poor abundance and availability of the dystrophin messenger in cytoplasm. This novel finding also has important repercussions for RNA-targeted therapies.
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Affiliation(s)
- Maria Sofia Falzarano
- Department of Medical Sciences, Unit of Medical Genetics, University of Ferrara, Ferrara, Italy
| | - Martina Mietto
- Department of Medical Sciences, Unit of Medical Genetics, University of Ferrara, Ferrara, Italy
| | - Fernanda Fortunato
- Department of Medical Sciences, Unit of Medical Genetics, University of Ferrara, Ferrara, Italy
| | - Marianna Farnè
- Department of Medical Sciences, Unit of Medical Genetics, University of Ferrara, Ferrara, Italy
| | - Fernanda Martini
- Department of Medical Sciences, Section of Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Pierpaolo Ala
- Dubowitz Neuromuscular Centre and National Institute for Health Research, Great Ormond Street Institute of Child Health, Biomedical Research Centre, University College London, London, UK
| | - Rita Selvatici
- Department of Medical Sciences, Unit of Medical Genetics, University of Ferrara, Ferrara, Italy
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre and National Institute for Health Research, Great Ormond Street Institute of Child Health, Biomedical Research Centre, University College London, London, UK
| | - Alessandra Ferlini
- Department of Medical Sciences, Unit of Medical Genetics, University of Ferrara, Ferrara, Italy.
- Dubowitz Neuromuscular Centre and National Institute for Health Research, Great Ormond Street Institute of Child Health, Biomedical Research Centre, University College London, London, UK.
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17
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Naskar A, Nayak A, Salaikumaran MR, Vishal SS, Gopal PP. Phase separation and pathologic transitions of RNP condensates in neurons: implications for amyotrophic lateral sclerosis, frontotemporal dementia and other neurodegenerative disorders. Front Mol Neurosci 2023; 16:1242925. [PMID: 37720552 PMCID: PMC10502346 DOI: 10.3389/fnmol.2023.1242925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/21/2023] [Indexed: 09/19/2023] Open
Abstract
Liquid-liquid phase separation results in the formation of dynamic biomolecular condensates, also known as membrane-less organelles, that allow for the assembly of functional compartments and higher order structures within cells. Multivalent, reversible interactions between RNA-binding proteins (RBPs), including FUS, TDP-43, and hnRNPA1, and/or RNA (e.g., RBP-RBP, RBP-RNA, RNA-RNA), result in the formation of ribonucleoprotein (RNP) condensates, which are critical for RNA processing, mRNA transport, stability, stress granule assembly, and translation. Stress granules, neuronal transport granules, and processing bodies are examples of cytoplasmic RNP condensates, while the nucleolus and Cajal bodies are representative nuclear RNP condensates. In neurons, RNP condensates promote long-range mRNA transport and local translation in the dendrites and axon, and are essential for spatiotemporal regulation of gene expression, axonal integrity and synaptic function. Mutations of RBPs and/or pathologic mislocalization and aggregation of RBPs are hallmarks of several neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and Alzheimer's disease. ALS/FTD-linked mutations of RBPs alter the strength and reversibility of multivalent interactions with other RBPs and RNAs, resulting in aberrant phase transitions. These aberrant RNP condensates have detrimental functional consequences on mRNA stability, localization, and translation, and ultimately lead to compromised axonal integrity and synaptic function in disease. Pathogenic protein aggregation is dependent on various factors, and aberrant dynamically arrested RNP condensates may serve as an initial nucleation step for pathologic aggregate formation. Recent studies have focused on identifying mechanisms by which neurons resolve phase transitioned condensates to prevent the formation of pathogenic inclusions/aggregates. The present review focuses on the phase separation of neurodegenerative disease-linked RBPs, physiological functions of RNP condensates, and the pathologic role of aberrant phase transitions in neurodegenerative disease, particularly ALS/FTD. We also examine cellular mechanisms that contribute to the resolution of aberrant condensates in neurons, and potential therapeutic approaches to resolve aberrantly phase transitioned condensates at a molecular level.
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Affiliation(s)
- Aditi Naskar
- Department of Pathology, Yale School of Medicine, New Haven, CT, United States
| | - Asima Nayak
- Department of Pathology, Yale School of Medicine, New Haven, CT, United States
| | | | - Sonali S. Vishal
- Department of Pathology, Yale School of Medicine, New Haven, CT, United States
| | - Pallavi P. Gopal
- Department of Pathology, Yale School of Medicine, New Haven, CT, United States
- Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale School of Medicine, New Haven, CT, United States
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18
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Sadasivan J, Hyrina A, DaSilva R, Jan E. An Insect Viral Protein Disrupts Stress Granule Formation in Mammalian Cells. J Mol Biol 2023; 435:168042. [PMID: 36898623 DOI: 10.1016/j.jmb.2023.168042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 02/23/2023] [Accepted: 03/02/2023] [Indexed: 03/12/2023]
Abstract
Stress granules (SGs) are cytosolic RNA-protein aggregates assembled during stress-induced translation arrest. Virus infection, in general, modulates and blocks SG formation. We previously showed that the model dicistrovirus Cricket paralysis virus (CrPV) 1A protein blocks stress granule formation in insect cells, which is dependent on a specific arginine 146 residue. CrPV-1A also inhibits SG formation in mammalian cells suggesting that this insect viral protein may be acting on a fundamental process that regulates SG formation. The mechanism underlying this process is not fully understood. Here, we show that overexpression of wild-type CrPV-1A, but not the CrPV-1A(R146A) mutant protein, inhibits distinct SG assembly pathways in HeLa cells. CrPV-1A mediated SG inhibition is independent of the Argonaute-2 (Ago-2) binding domain and the E3 ubiquitin ligase recruitment domain. CrPV-1A expression leads to nuclear poly(A)+ RNA accumulation and is correlated with the localization of CrPV-1A to the nuclear periphery. Finally, we show that the overexpression of CrPV-1A blocks FUS and TDP-43 granules, which are pathological hallmarks of neurodegenerative diseases. We propose a model whereby CrPV-1A expression in mammalian cells blocks SG formation by depleting cytoplasmic mRNA scaffolds via mRNA export inhibition. CrPV-1A provides a new molecular tool to study RNA-protein aggregates and potentially uncouple SG functions.
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Affiliation(s)
- Jibin Sadasivan
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada. https://twitter.com/@jibin_sadasivan
| | - Anastasia Hyrina
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Rachel DaSilva
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Eric Jan
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada.
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19
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Loedige I, Baranovskii A, Mendonsa S, Dantsuji S, Popitsch N, Breimann L, Zerna N, Cherepanov V, Milek M, Ameres S, Chekulaeva M. mRNA stability and m 6A are major determinants of subcellular mRNA localization in neurons. Mol Cell 2023; 83:2709-2725.e10. [PMID: 37451262 PMCID: PMC10529935 DOI: 10.1016/j.molcel.2023.06.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/04/2023] [Accepted: 06/19/2023] [Indexed: 07/18/2023]
Abstract
For cells to perform their biological functions, they need to adopt specific shapes and form functionally distinct subcellular compartments. This is achieved in part via an asymmetric distribution of mRNAs within cells. Currently, the main model of mRNA localization involves specific sequences called "zipcodes" that direct mRNAs to their proper locations. However, while thousands of mRNAs localize within cells, only a few zipcodes have been identified, suggesting that additional mechanisms contribute to localization. Here, we assess the role of mRNA stability in localization by combining the isolation of the soma and neurites of mouse primary cortical and mESC-derived neurons, SLAM-seq, m6A-RIP-seq, the perturbation of mRNA destabilization mechanisms, and the analysis of multiple mRNA localization datasets. We show that depletion of mRNA destabilization elements, such as m6A, AU-rich elements, and suboptimal codons, functions as a mechanism that mediates the localization of mRNAs associated with housekeeping functions to neurites in several types of neurons.
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Affiliation(s)
- Inga Loedige
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany
| | - Artem Baranovskii
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany
| | - Samantha Mendonsa
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany
| | - Sayaka Dantsuji
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany
| | - Niko Popitsch
- Max Perutz Labs, University of Vienna, Vienna BioCenter, 1030 Vienna, Austria
| | - Laura Breimann
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Nadja Zerna
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany
| | - Vsevolod Cherepanov
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany
| | - Miha Milek
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany
| | - Stefan Ameres
- Max Perutz Labs, University of Vienna, Vienna BioCenter, 1030 Vienna, Austria
| | - Marina Chekulaeva
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany.
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20
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Liu Y, Yao Z, Lian G, Yang P. Biomolecular phase separation in stress granule assembly and virus infection. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1099-1118. [PMID: 37401177 PMCID: PMC10415189 DOI: 10.3724/abbs.2023117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 05/06/2023] [Indexed: 07/05/2023] Open
Abstract
Liquid-liquid phase separation (LLPS) has emerged as a crucial mechanism for cellular compartmentalization. One prominent example of this is the stress granule. Found in various types of cells, stress granule is a biomolecular condensate formed through phase separation. It comprises numerous RNA and RNA-binding proteins. Over the past decades, substantial knowledge has been gained about the composition and dynamics of stress granules. SGs can regulate various signaling pathways and have been associated with numerous human diseases, such as neurodegenerative diseases, cancer, and infectious diseases. The threat of viral infections continues to loom over society. Both DNA and RNA viruses depend on host cells for replication. Intriguingly, many stages of the viral life cycle are closely tied to RNA metabolism in human cells. The field of biomolecular condensates has rapidly advanced in recent times. In this context, we aim to summarize research on stress granules and their link to viral infections. Notably, stress granules triggered by viral infections behave differently from the canonical stress granules triggered by sodium arsenite (SA) and heat shock. Studying stress granules in the context of viral infections could offer a valuable platform to link viral replication processes and host anti-viral responses. A deeper understanding of these biological processes could pave the way for innovative interventions and treatments for viral infectious diseases. They could potentially bridge the gap between basic biological processes and interactions between viruses and their hosts.
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Affiliation(s)
- Yi Liu
- />Westlake Laboratory of Life Sciences and BiomedicineSchool of Life SciencesWestlake UniversityHangzhou310030China
| | - Zhiying Yao
- />Westlake Laboratory of Life Sciences and BiomedicineSchool of Life SciencesWestlake UniversityHangzhou310030China
| | - Guiwei Lian
- />Westlake Laboratory of Life Sciences and BiomedicineSchool of Life SciencesWestlake UniversityHangzhou310030China
| | - Peiguo Yang
- />Westlake Laboratory of Life Sciences and BiomedicineSchool of Life SciencesWestlake UniversityHangzhou310030China
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21
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Abstract
Messenger RNA (mRNA) stability and translational efficiency are two crucial aspects of the post-transcriptional process that profoundly impact protein production in a cell. While it is widely known that ribosomes produce proteins, studies during the past decade have surprisingly revealed that ribosomes also control mRNA stability in a codon-dependent manner, a process referred to as codon optimality. Therefore, codons, the three-nucleotide words read by the ribosome, have a potent effect on mRNA stability and provide cis-regulatory information that extends beyond the amino acids they encode. While the codon optimality molecular mechanism is still unclear, the translation elongation rate appears to trigger mRNA decay. Thus, transfer RNAs emerge as potential master gene regulators affecting mRNA stability. Furthermore, while few factors related to codon optimality have been identified in yeast, the orthologous genes in vertebrates do not necessary share the same functions. Here, we discuss codon optimality findings and gene regulation layers related to codon composition in different eukaryotic species.
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Affiliation(s)
- Qiushuang Wu
- Stowers Institute for Medical Research, Kansas City, Missouri, USA;
| | - Ariel A Bazzini
- Stowers Institute for Medical Research, Kansas City, Missouri, USA;
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, USA
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22
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Li Y, Xu M, Qi Z. Deciphering molecular mechanisms of phase separation in RNA biology by single-molecule biophysical technologies. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1034-1041. [PMID: 37337634 PMCID: PMC10415185 DOI: 10.3724/abbs.2023113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 03/06/2023] [Indexed: 06/21/2023] Open
Abstract
Ribonucleic acid (RNA) biology has emerged as one of the most important areas in modern biology and biomedicine. RNA and RNA-binding proteins (RBPs) are involved in forming biomolecular condensates, which are crucial for RNA metabolism. To quantitively decipher the molecular mechanisms of RNP granules, researchers have turned to single-molecule biophysical techniques, such as single-molecule Förster resonance energy transfer (smFRET), in vivo single-molecule imaging technique with single particle tracking (SPT), DNA Curtains, optical tweezers, and atomic force microscopy (AFM). These methods are used to investigate the molecular biophysical properties within RNP granules, as well as the molecular interactions between RNA and RBPs and RBPs themselves, which are challenging to study using traditional experimental methods of the liquid-liquid phase separation (LLPS) field, such as fluorescence recovery after photobleaching (FRAP). In this work, we summarize the applications of single-molecule biophysical techniques in RNP granule studies and highlight how these methods can be used to reveal the molecular mechanisms of RNP granules.
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Affiliation(s)
- Yuchen Li
- Center for Quantitative Biology and Peking-Tsinghua Center for Life SciencesAcademy for Advanced Interdisciplinary StudiesPeking UniversityBeijing100871China
| | - Mengmeng Xu
- Tsinghua-Peking Center for Life SciencesTsinghua UniversityBeijing100084China
| | - Zhi Qi
- Center for Quantitative Biology and Peking-Tsinghua Center for Life SciencesAcademy for Advanced Interdisciplinary StudiesPeking UniversityBeijing100871China
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23
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Zheng H, Peng K, Gou X, Ju C, Zhang H. RNA recruitment switches the fate of protein condensates from autophagic degradation to accumulation. J Cell Biol 2023; 222:e202210104. [PMID: 37014300 PMCID: PMC10075224 DOI: 10.1083/jcb.202210104] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 02/07/2023] [Accepted: 03/01/2023] [Indexed: 04/05/2023] Open
Abstract
Protein condensates can evade autophagic degradation under stress or pathological conditions. However, the underlying mechanisms are unclear. Here, we demonstrate that RNAs switch the fate of condensates in Caenorhabditis elegans. PGL granules undergo autophagic degradation in embryos laid under normal conditions and accumulate in embryos laid under heat stress conditions to confer stress adaptation. In heat-stressed embryos, mRNAs and RNA control factors partition into PGL granules. Depleting proteins involved in mRNA biogenesis and stability suppresses PGL granule accumulation and triggers their autophagic degradation, while loss of activity of proteins involved in RNA turnover facilitates accumulation. RNAs facilitate LLPS of PGL granules, enhance their liquidity, and also inhibit recruitment of the gelation-promoting scaffold protein EPG-2 to PGL granules. Thus, RNAs are important for controlling the susceptibility of phase-separated protein condensates to autophagic degradation. Our work provides insights into the accumulation of ribonucleoprotein aggregates associated with the pathogenesis of various diseases.
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Affiliation(s)
- Hui Zheng
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Kangfu Peng
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xiaomeng Gou
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Chen Ju
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Hong Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
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24
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Sharma H, Yadav V, D'Souza-Schorey C, Go DB, Senapati S, Chang HC. A Scalable High-Throughput Isoelectric Fractionation Platform for Extracellular Nanocarriers: Comprehensive and Bias-Free Isolation of Ribonucleoproteins from Plasma, Urine, and Saliva. ACS NANO 2023; 17:9388-9404. [PMID: 37071723 PMCID: PMC10756736 DOI: 10.1021/acsnano.3c01340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Extracellular nanocarriers (extracellular vesicles (EVs), lipoproteins, and ribonucleoproteins) of protein and nucleic acids mediate intercellular communication and are clinically adaptable as distinct circulating biomarkers. However, the overlapping size and density of the nanocarriers have so far prevented their efficient physical fractionation, thus impeding independent downstream molecular assays. Here, we report a bias-free high-throughput and high-yield continuous isoelectric fractionation nanocarrier fractionation technique based on their distinct isoelectric points. This nanocarrier fractionation platform is enabled by a robust and tunable linear pH profile provided by water-splitting at a bipolar membrane and stabilized by flow without ampholytes. The linear pH profile that allows easy tuning is a result of rapid equilibration of the water dissociation reaction and stabilization by flow. The platform is automated with a machine learning procedure to allow recalibration for different physiological fluids and nanocarriers. The optimized technique has a resolution of 0.3 ΔpI, sufficient to separate all nanocarriers and even subclasses of nanocarriers. Its performance is then evaluated with several biofluids, including plasma, urine, and saliva samples. Comprehensive, high-purity (plasma: >93%, urine: >95% and saliva: >97%), high-yield (plasma: >78%, urine: >87% and saliva: >96%), and probe-free isolation of ribonucleoproteins in 0.75 mL samples of various biofluids in 30 min is demonstrated, significantly outperforming affinity-based and highly biased gold standards having low yield and day-long protocols. Binary fractionation of EVs and different lipoproteins is also achieved with similar performance.
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Affiliation(s)
- Himani Sharma
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Vivek Yadav
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Crislyn D'Souza-Schorey
- Harper Cancer Research Institute, University of Notre Dame, Notre Dame, Indiana 46556, United States
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - David B Go
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Satyajyoti Senapati
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Hsueh-Chia Chang
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
- Harper Cancer Research Institute, University of Notre Dame, Notre Dame, Indiana 46556, United States
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25
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Cerulo L, Pezzella N, Caruso FP, Parente P, Remo A, Giordano G, Forte N, Busselez J, Boschi F, Galiè M, Franco B, Pancione M. Single-cell proteo-genomic reveals a comprehensive map of centrosome-associated spliceosome components. iScience 2023; 26:106602. [PMID: 37250316 PMCID: PMC10214398 DOI: 10.1016/j.isci.2023.106602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 01/16/2023] [Accepted: 03/29/2023] [Indexed: 05/31/2023] Open
Abstract
Ribonucleoprotein (RNP) condensates are crucial for controlling RNA metabolism and splicing events in animal cells. We used spatial proteomics and transcriptomic to elucidate RNP interaction networks at the centrosome, the main microtubule-organizing center in animal cells. We found a number of cell-type specific centrosome-associated spliceosome interactions localized in subcellular structures involved in nuclear division and ciliogenesis. A component of the nuclear spliceosome BUD31 was validated as an interactor of the centriolar satellite protein OFD1. Analysis of normal and disease cohorts identified the cholangiocarcinoma as target of centrosome-associated spliceosome alterations. Multiplexed single-cell fluorescent microscopy for the centriole linker CEP250 and spliceosome components including BCAS2, BUD31, SRSF2 and DHX35 recapitulated bioinformatic predictions on the centrosome-associated spliceosome components tissue-type specific composition. Collectively, centrosomes and cilia act as anchor for cell-type specific spliceosome components, and provide a helpful reference for explore cytoplasmic condensates functions in defining cell identity and in the origin of rare diseases.
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Affiliation(s)
- Luigi Cerulo
- Bioinformatics Laboratory, BIOGEM scrl, Ariano Irpino, Avellino, Italy
- Department of Sciences and Technologies, University of Sannio, Benevento, Italy
| | - Nunziana Pezzella
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei, 34, Pozzuoli, 80078 Naples, Italy
- School for Advanced Studies, Genomics and Experimental Medicine Program, Naples, Italy
| | - Francesca Pia Caruso
- Bioinformatics Laboratory, BIOGEM scrl, Ariano Irpino, Avellino, Italy
- Department of Sciences and Technologies, University of Sannio, Benevento, Italy
| | - Paola Parente
- Unit of Pathology, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia, Italy
| | - Andrea Remo
- Pathology Unit, Mater Salutis Hospital AULSS9, “Scaligera”, 37122 Verona, Italy
| | - Guido Giordano
- Unit of Medical Oncology and Biomolecular Therapy, Department of Medical and Surgical Sciences, University of Foggia, Policlinico Riuniti, 71122 Foggia, Italy
| | - Nicola Forte
- Department of Clinical Pathology, Fatebenefratelli Hospital, 82100 Benevento, Italy
| | - Johan Busselez
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
| | - Federico Boschi
- Department of Computer Science, University of Verona, Strada Le Grazie 8, Verona, Italy
| | - Mirco Galiè
- Department of Neuroscience, Biomedicine and Movement, University of Verona, Verona, Italy
| | - Brunella Franco
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei, 34, Pozzuoli, 80078 Naples, Italy
- School for Advanced Studies, Genomics and Experimental Medicine Program, Naples, Italy
- Medical Genetics, Department of Translational Medicine, University of Naples “Federico II”, Via Sergio Pansini, 80131 Naples, Italy
| | - Massimo Pancione
- Department of Sciences and Technologies, University of Sannio, Benevento, Italy
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, Complutense University Madrid, 28040 Madrid, Spain
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26
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Kim T, Yoo J, Do S, Hwang DS, Park Y, Shin Y. RNA-mediated demixing transition of low-density condensates. Nat Commun 2023; 14:2425. [PMID: 37105967 PMCID: PMC10140143 DOI: 10.1038/s41467-023-38118-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 04/17/2023] [Indexed: 04/29/2023] Open
Abstract
Biomolecular condensates play a key role in organizing cellular reactions by concentrating a specific set of biomolecules. However, whether condensate formation is accompanied by an increase in the total mass concentration within condensates or by the demixing of already highly crowded intracellular components remains elusive. Here, using refractive index imaging, we quantify the mass density of several condensates, including nucleoli, heterochromatin, nuclear speckles, and stress granules. Surprisingly, the latter two condensates exhibit low densities with a total mass concentration similar to the surrounding cyto- or nucleoplasm. Low-density condensates display higher permeability to cellular protein probes. We find that RNA tunes the biomolecular density of condensates. Moreover, intracellular structures such as mitochondria heavily influence the way phase separation proceeds, impacting the localization, morphology, and growth of condensates. These findings favor a model where segregative phase separation driven by non-associative or repulsive molecular interactions together with RNA-mediated selective association of specific components can give rise to low-density condensates in the crowded cellular environment.
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Affiliation(s)
- Taehyun Kim
- Department of Mechanical Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jaeyoon Yoo
- Department of Mechanical Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sungho Do
- Department of Mechanical Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Dong Soo Hwang
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - YongKeun Park
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
- KAIST Institute for Health Science and Technology, Daejeon, 34141, Republic of Korea
- Tomocube Inc, Daejeon, 34109, South Korea
| | - Yongdae Shin
- Department of Mechanical Engineering, Seoul National University, Seoul, 08826, Republic of Korea.
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul, 08826, Korea.
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27
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Fujikawa D, Nakamura T, Yoshioka D, Li Z, Moriizumi H, Taguchi M, Tokai-Nishizumi N, Kozuka-Hata H, Oyama M, Takekawa M. Stress granule formation inhibits stress-induced apoptosis by selectively sequestering executioner caspases. Curr Biol 2023; 33:1967-1981.e8. [PMID: 37119817 DOI: 10.1016/j.cub.2023.04.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/23/2023] [Accepted: 04/06/2023] [Indexed: 05/01/2023]
Abstract
Cytoplasmic stress granules (SGs) are phase-separated membrane-less organelles that form in response to various stress stimuli. SGs are mainly composed of non-canonical stalled 48S preinitiation complexes. In addition, many other proteins also accumulate into SGs, but the list is still incomplete. SG assembly suppresses apoptosis and promotes cell survival under stress. Furthermore, hyperformation of SGs is frequently observed in various human cancers and accelerates tumor development and progression by reducing stress-induced damage of cancer cells. Therefore, they are of clinical importance. However, the precise mechanism underlying SG-mediated inhibition of apoptosis remains ill-defined. Here, using a proximity-labeling proteomic approach, we comprehensively analyzed SG-resident proteins and identified the executioner caspases, caspase-3 and -7, as SG components. We demonstrate that accumulation of caspase-3/7 into SGs is mediated by evolutionarily conserved amino acid residues within their large catalytic domains and inhibits caspase activities and consequent apoptosis induced by various stresses. Expression of an SG-localization-deficient caspase-3 mutant in cells largely counteracted the anti-apoptotic effect of SGs, whereas enforced relocalization of the caspase-3 mutant to SGs restored it. Thus, SG-mediated sequestration of executioner caspases is a mechanism underlying the broad cytoprotective function of SGs. Furthermore, using a mouse xenograft tumor model, we show that this mechanism prevents cancer cells from apoptosis in tumor tissues, thereby promoting cancer progression. Our results reveal the functional crosstalk between SG-mediated cell survival and caspase-mediated cell death signaling pathways and delineate a molecular mechanism that dictates cell-fate decisions under stress and promotes tumorigenesis.
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Affiliation(s)
- Daichi Fujikawa
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan; Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takanori Nakamura
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Daisuke Yoshioka
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa 277-8562, Chiba, Japan
| | - Zizheng Li
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa 277-8562, Chiba, Japan
| | - Hisashi Moriizumi
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa 277-8562, Chiba, Japan
| | - Mari Taguchi
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan; Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Noriko Tokai-Nishizumi
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Hiroko Kozuka-Hata
- Medical Proteomics Laboratory, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Masaaki Oyama
- Medical Proteomics Laboratory, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Mutsuhiro Takekawa
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan; Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa 277-8562, Chiba, Japan; Medical Proteomics Laboratory, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
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28
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Robinson AO, Lee J, Cameron A, Keating CD, Adamala KP. Cell-free expressed membraneless organelles sequester RNA in synthetic cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.03.535479. [PMID: 37066403 PMCID: PMC10104018 DOI: 10.1101/2023.04.03.535479] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Compartments within living cells create specialized microenvironments, allowing for multiple reactions to be carried out simultaneously and efficiently. While some organelles are bound by a lipid bilayer, others are formed by liquid-liquid phase separation, such as P-granules and nucleoli. Synthetic minimal cells have been widely used to study many natural processes, including organelle formation. Here we describe a synthetic cell expressing RGG-GFP-RGG, a phase-separating protein derived from LAF-1 RGG domains, to form artificial membraneless organelles that can sequester RNA and reduce protein expression. We create complex microenvironments within synthetic cell cytoplasm and introduce a tool to modulate protein expression in synthetic cells. Engineering of compartments within synthetic cells furthers understanding of evolution and function of natural organelles, as well as it facilitates the creation of more complex and multifaceted synthetic life-like systems.
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Affiliation(s)
- Abbey O Robinson
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jessica Lee
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - Anders Cameron
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Christine D Keating
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - Katarzyna P Adamala
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
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29
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DEAD-box ATPases as regulators of biomolecular condensates and membrane-less organelles. Trends Biochem Sci 2023; 48:244-258. [PMID: 36344372 DOI: 10.1016/j.tibs.2022.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 09/30/2022] [Accepted: 10/03/2022] [Indexed: 11/06/2022]
Abstract
RNA-dependent DEAD-box ATPases (DDXs) are emerging as major regulators of RNA-containing membrane-less organelles (MLOs). On the one hand, oligomerizing DDXs can promote condensate formation 'in cis', often using RNA as a scaffold. On the other hand, DDXs can disrupt RNA-RNA and RNA-protein interactions and thereby 'in trans' remodel the multivalent interactions underlying MLO formation. In this review, we discuss the best studied examples of DDXs modulating MLOs in cis and in trans. Further, we illustrate how this contributes to the dynamic assembly and turnover of MLOs which might help cells to modulate RNA sequestration and processing in a temporal and spatial manner.
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30
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Layana C, Vilardo ES, Corujo G, Hernández G, Rivera-Pomar R. Drosophila Me31B is a Dual eIF4E-Interacting Protein. J Mol Biol 2023; 435:167949. [PMID: 36638908 DOI: 10.1016/j.jmb.2023.167949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/14/2022] [Accepted: 01/03/2023] [Indexed: 01/12/2023]
Abstract
Eukaryotic translation initiation factor 4E (eIF4E) is a key factor involved in different aspects of mRNA metabolism. Drosophila melanogaster genome encodes eight eIF4E isoforms, and the canonical isoform eIF4E-1 is a ubiquitous protein that plays a key role in mRNA translation. eIF4E-3 is specifically expressed in testis and controls translation during spermatogenesis. In eukaryotic cells, translational control and mRNA decay is highly regulated in different cytoplasmic ribonucleoprotein foci, which include the processing bodies (PBs). In this study, we show that Drosophila eIF4E-1 and eIF4E-3 occur in PBs along the DEAD-box RNA helicase Me31B. We show that Me31B interacts with eIF4E-1 and eIF4E-3 by means of yeast two-hybrid system, FRET in D. melanogaster S2 cells and coimmunoprecipitation in testis. Truncation and point mutations of Me31B proteins show two eIF4E-binding sites located in different protein domains. Residues Y401-L407 (at the carboxy-terminus) are essential for interaction with eIF4E-1, whereas residues F63-L70 (at the amino-terminus) are critical for interaction with eIF4E-3. The residue W117 in eIF4E-1 and the homolog position F103 in eIF4E-3 are necessary for Me31B-eIF4E interaction suggesting that the change of tryptophan to phenylalanine provides specificity. Me31B represents a novel type of eIF4E-interacting protein with dual and specific interaction domains that might be recognized by different eIF4E isoforms in different tissues, adding complexity to the control of gene expression in eukaryotes.
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Affiliation(s)
- Carla Layana
- Centro Regional de Estudios Genómicos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Boulevard 120 N° 1459, 1900 La Plata, Argentina.
| | - Emiliano Salvador Vilardo
- Centro Regional de Estudios Genómicos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Boulevard 120 N° 1459, 1900 La Plata, Argentina
| | - Gonzalo Corujo
- Centro Regional de Estudios Genómicos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Boulevard 120 N° 1459, 1900 La Plata, Argentina
| | - Greco Hernández
- Translation and Cancer Laboratory, Unit of Biomedical Research on Cancer, National Institute of Cancer (Instituto Nacional de Cancerología, INCan), 22 San Fernando Ave., Tlalpan, 14080 Mexico City, Mexico
| | - Rolando Rivera-Pomar
- Centro Regional de Estudios Genómicos, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Boulevard 120 N° 1459, 1900 La Plata, Argentina; Centro de Investigación y Transferencia del Noroeste de Buenos Aires (CITNOBA) - Centro de Bioinvestigaciones, Universidad Nacional del Noroeste de Buenos Aires, Av. Presidente Frondizi Km 4, 2700 Pergamino, Argentina; Molecular Developmental Biology Emeritus Group, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany
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31
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Manjunath L, Oh S, Ortega P, Bouin A, Bournique E, Sanchez A, Martensen PM, Auerbach AA, Becker JT, Seldin M, Harris RS, Semler BL, Buisson R. APOBEC3B drives PKR-mediated translation shutdown and protects stress granules in response to viral infection. Nat Commun 2023; 14:820. [PMID: 36781883 PMCID: PMC9925369 DOI: 10.1038/s41467-023-36445-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 01/31/2023] [Indexed: 02/15/2023] Open
Abstract
Double-stranded RNA produced during viral replication and transcription activates both protein kinase R (PKR) and ribonuclease L (RNase L), which limits viral gene expression and replication through host shutoff of translation. In this study, we find that APOBEC3B forms a complex with PABPC1 to stimulate PKR and counterbalances the PKR-suppressing activity of ADAR1 in response to infection by many types of viruses. This leads to translational blockage and the formation of stress granules. Furthermore, we show that APOBEC3B localizes to stress granules through the interaction with PABPC1. APOBEC3B facilitates the formation of protein-RNA condensates with stress granule assembly factor (G3BP1) by protecting mRNA associated with stress granules from RNAse L-induced RNA cleavage during viral infection. These results not only reveal that APOBEC3B is a key regulator of different steps of the innate immune response throughout viral infection but also highlight an alternative mechanism by which APOBEC3B can impact virus replication without editing viral genomes.
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Affiliation(s)
- Lavanya Manjunath
- Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, CA, USA
- Center for Virus Research, University of California Irvine, Irvine, CA, USA
- Center for Epigenetics and Metabolism, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA, USA
| | - Sunwoo Oh
- Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, CA, USA
- Center for Virus Research, University of California Irvine, Irvine, CA, USA
- Center for Epigenetics and Metabolism, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA, USA
| | - Pedro Ortega
- Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, CA, USA
- Center for Virus Research, University of California Irvine, Irvine, CA, USA
- Center for Epigenetics and Metabolism, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA, USA
| | - Alexis Bouin
- Center for Virus Research, University of California Irvine, Irvine, CA, USA
- Department of Microbiology & Molecular Genetics, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Elodie Bournique
- Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, CA, USA
- Center for Virus Research, University of California Irvine, Irvine, CA, USA
- Center for Epigenetics and Metabolism, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA, USA
| | - Ambrocio Sanchez
- Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, CA, USA
- Center for Virus Research, University of California Irvine, Irvine, CA, USA
- Center for Epigenetics and Metabolism, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA, USA
| | - Pia Møller Martensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Ashley A Auerbach
- Department of Biochemistry and Structural Biology, University of Texas Health San Antonio, San Antonio, TX, USA
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Jordan T Becker
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN, USA
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Marcus Seldin
- Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, CA, USA
- Center for Epigenetics and Metabolism, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA, USA
| | - Reuben S Harris
- Department of Biochemistry and Structural Biology, University of Texas Health San Antonio, San Antonio, TX, USA
- Howard Hughes Medical Institute, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Bert L Semler
- Center for Virus Research, University of California Irvine, Irvine, CA, USA
- Department of Microbiology & Molecular Genetics, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Rémi Buisson
- Department of Biological Chemistry, School of Medicine, University of California Irvine, Irvine, CA, USA.
- Center for Virus Research, University of California Irvine, Irvine, CA, USA.
- Center for Epigenetics and Metabolism, Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA, USA.
- Department of Pharmaceutical Sciences, School of Pharmacy & Pharmaceutical Sciences, University of California Irvine, Irvine, CA, USA.
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32
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Bourke AM, Schwarz A, Schuman EM. De-centralizing the Central Dogma: mRNA translation in space and time. Mol Cell 2023; 83:452-468. [PMID: 36669490 DOI: 10.1016/j.molcel.2022.12.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 12/16/2022] [Accepted: 12/28/2022] [Indexed: 01/20/2023]
Abstract
As our understanding of the cell interior has grown, we have come to appreciate that most cellular operations are localized, that is, they occur at discrete and identifiable locations or domains. These cellular domains contain enzymes, machines, and other components necessary to carry out and regulate these localized operations. Here, we review these features of one such operation: the localization and translation of mRNAs within subcellular compartments observed across cell types and organisms. We describe the conceptual advantages and the "ingredients" and mechanisms of local translation. We focus on the nature and features of localized mRNAs, how they travel and get localized, and how this process is regulated. We also evaluate our current understanding of protein synthesis machines (ribosomes) and their cadre of regulatory elements, that is, the translation factors.
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Affiliation(s)
- Ashley M Bourke
- Max Planck Institute for Brain Research, Max von Laue Strasse 4, 60438 Frankfurt, Germany
| | - Andre Schwarz
- Max Planck Institute for Brain Research, Max von Laue Strasse 4, 60438 Frankfurt, Germany
| | - Erin M Schuman
- Max Planck Institute for Brain Research, Max von Laue Strasse 4, 60438 Frankfurt, Germany.
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Roles of RNA-binding proteins in neurological disorders, COVID-19, and cancer. Hum Cell 2023; 36:493-514. [PMID: 36528839 PMCID: PMC9760055 DOI: 10.1007/s13577-022-00843-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022]
Abstract
RNA-binding proteins (RBPs) have emerged as important players in multiple biological processes including transcription regulation, splicing, R-loop homeostasis, DNA rearrangement, miRNA function, biogenesis, and ribosome biogenesis. A large number of RBPs had already been identified by different approaches in various organisms and exhibited regulatory functions on RNAs' fate. RBPs can either directly or indirectly interact with their target RNAs or mRNAs to assume a key biological function whose outcome may trigger disease or normal biological events. They also exert distinct functions related to their canonical and non-canonical forms. This review summarizes the current understanding of a wide range of RBPs' functions and highlights their emerging roles in the regulation of diverse pathways, different physiological processes, and their molecular links with diseases. Various types of diseases, encompassing colorectal carcinoma, non-small cell lung carcinoma, amyotrophic lateral sclerosis, and Severe acute respiratory syndrome coronavirus 2, aberrantly express RBPs. We also highlight some recent advances in the field that could prompt the development of RBPs-based therapeutic interventions.
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Baker M, Khosravi R, Salton M. Native RNA Immunoprecipitation (RIP) for Precise Detection and Quantification of Protein-Interacting RNA. Methods Mol Biol 2023; 2666:107-114. [PMID: 37166660 DOI: 10.1007/978-1-0716-3191-1_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Proteins with either RNA or DNA-binding motifs were shown to bind RNA. Immunoprecipitation of such proteins using antibodies and identification of the RNA-binding molecules is called RNA immunoprecipitation (RIP). The RNA precipitated with the studied protein can be detected by real-time polymerase chain reaction (PCR), microarray or sequencing. Here, we detail a method for native immunoprecipitation, without cross-linking, to isolate protein-RNA complexes followed by subsequent extraction and quantification of the co-purified RNA.
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Affiliation(s)
- Mai Baker
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Rami Khosravi
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Maayan Salton
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
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35
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Oliveira C, Holetz FB, Alves LR, Ávila AR. Modulation of Virulence Factors during Trypanosoma cruzi Differentiation. Pathogens 2022; 12:pathogens12010032. [PMID: 36678380 PMCID: PMC9865030 DOI: 10.3390/pathogens12010032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/19/2022] [Accepted: 12/20/2022] [Indexed: 12/28/2022] Open
Abstract
Chagas disease is a neglected tropical disease caused by Trypanosoma cruzi. This protozoan developed several mechanisms to infect, propagate, and survive in different hosts. The specific expression of proteins is responsible for morphological and metabolic changes in different parasite stages along the parasite life cycle. The virulence strategies at the cellular and molecular levels consist of molecules responsible for mediating resistance mechanisms to oxidative damage, cellular invasion, and immune evasion, performed mainly by surface proteins. Since parasite surface coat remodeling is crucial to invasion and infectivity, surface proteins are essential virulence elements. Understanding the factors involved in these processes improves the knowledge of parasite pathogenesis. Genome sequencing has opened the door to high-throughput technologies, allowing us to obtain a deeper understanding of gene reprogramming along the parasite life cycle and identify critical molecules for survival. This review therefore focuses on proteins regulated during differentiation into infective forms considered virulence factors and addresses the current known mechanisms acting in the modulation of gene expression, emphasizing mRNA signals, regulatory factors, and protein complexes.
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Affiliation(s)
- Camila Oliveira
- Laboratório de Regulação da Expressão Gênica, Instituto Carlos Chagas, Fiocruz Paraná, Curitiba 81350-010, Brazil
- Centre de Recherche CERVO, Université Laval, Québec City, QC G1V 0A6, Canada
| | - Fabíola Barbieri Holetz
- Laboratório de Regulação da Expressão Gênica, Instituto Carlos Chagas, Fiocruz Paraná, Curitiba 81350-010, Brazil
| | - Lysangela Ronalte Alves
- Laboratório de Regulação da Expressão Gênica, Instituto Carlos Chagas, Fiocruz Paraná, Curitiba 81350-010, Brazil
- Research Center in Infectious Diseases, Division of Infectious Disease and Immunity CHU de Quebec Research Center, University Laval, Québec City, QC G1V 4G2, Canada
| | - Andréa Rodrigues Ávila
- Laboratório de Pesquisa em Apicomplexa, Instituto Carlos Chagas, Fiocruz Paraná, Curitiba 81350-010, Brazil
- Correspondence: ; Tel.: +55-41-33163230
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36
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Tom JA, Onuchic PL, Deniz AA. Short PolyA RNA Homopolymers Undergo Mg 2+-Mediated Kinetically Arrested Condensation. J Phys Chem B 2022; 126:9715-9725. [PMID: 36378781 PMCID: PMC9706566 DOI: 10.1021/acs.jpcb.2c05935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RNA-RNA interactions have increasingly been recognized for their potential to shape the mesoscale properties of biomolecular condensates, influencing morphology, organization, and material state through networking interactions. While most studies have focused on networking via Watson-Crick base pairing interactions, previous work has suggested a potential for noncanonical RNA-RNA interactions to also give rise to condensation and alter overall material state. Here, we test the phase separation of short polyA RNA (polyrA) homopolymers. We discover and characterize the potential for short polyrA sequences to form RNA condensates at lower Mg2+ concentrations than previously observed, which appear as internally arrested droplets with slow polyrA diffusion despite continued fusion. Our work also reveals a negative cooperativity effect between the effects of Mg2+ and Na+ on polyrA condensation. Finally, we observe that polyrA sequences can act as promoters of phase separation in mixed sequences. These results demonstrate the potential for noncanonical interactions to act as networking stickers, leading to specific condensation properties inherent to polyrA composition and structure, with implications for the fundamental physical chemistry of the system and function of polyA RNA in biology.
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Gordon-Kim C, Rha A, Poppitz GA, Smith-Carpenter J, Luu R, Roberson AB, Conklin R, Blake A, Lynn DG. Polyanion order controls liquid-to-solid phase transition in peptide/nucleic acid co-assembly. Front Mol Biosci 2022; 9:991728. [PMID: 36452451 PMCID: PMC9702359 DOI: 10.3389/fmolb.2022.991728] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 10/25/2022] [Indexed: 01/06/2024] Open
Abstract
The Central Dogma highlights the mutualistic functions of protein and nucleic acid biopolymers, and this synergy appears prominently in the membraneless organelles widely distributed throughout prokaryotic and eukaryotic organisms alike. Ribonucleoprotein granules (RNPs), which are complex coacervates of RNA with proteins, are a prime example of these membranelles organelles and underly multiple essential cellular functions. Inspired by the highly dynamic character of these organelles and the recent studies that ATP both inhibits and templates phase separation of the fused in sarcoma (FUS) protein implicated in several neurodegenerative diseases, we explored the RNA templated ordering of a single motif of the Aβ peptide of Alzheimer's disease. We now know that this strong cross-β propensity motif alone assembles through a liquid-like coacervate phase that can be externally templated to form distinct supramolecular assemblies. Now we provide evidence that structured phosphates, ranging from complex structures like double stranded and quadraplex DNA to simple trimetaphosphate, differentially impact the liquid to solid phase transition necessary for paracrystalline assembly. The results from this simple model illustrate the potential of ordered environmental templates in the transition to potentially irreversible pathogenic assemblies and provides insight into the ordering dynamics necessary for creating functional synthetic polymer co-assemblies.
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Affiliation(s)
| | - Allisandra Rha
- Children’s Health of Orange County, Research Institute, Orange, CA, United States
| | - George A. Poppitz
- Department of Chemistry, Emory University, Atlanta, GA, United States
| | | | - Regina Luu
- Department of Chemistry, Emory University, Atlanta, GA, United States
| | | | - Russell Conklin
- Department of Chemistry, Emory University, Atlanta, GA, United States
| | - Alexis Blake
- Department of Chemistry, Emory University, Atlanta, GA, United States
| | - David G. Lynn
- Department of Chemistry, Emory University, Atlanta, GA, United States
- Department of Biology, Emory University, Atlanta, GA, United States
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Shiftless Restricts Viral Gene Expression and Influences RNA Granule Formation during Kaposi’s Sarcoma-Associated Herpesvirus Lytic Replication. J Virol 2022; 96:e0146922. [PMID: 36326276 PMCID: PMC9682979 DOI: 10.1128/jvi.01469-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the past 5 years, SHFL has emerged as a novel and integral piece of the innate immune response to viral infection. SHFL has been reported to restrict the replication of multiple viruses, including several flaviviruses and the retrovirus HIV-1.
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39
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Hees JT, Harbauer AB. Metabolic Regulation of Mitochondrial Protein Biogenesis from a Neuronal Perspective. Biomolecules 2022; 12:1595. [PMID: 36358945 PMCID: PMC9687362 DOI: 10.3390/biom12111595] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 09/29/2023] Open
Abstract
Neurons critically depend on mitochondria for ATP production and Ca2+ buffering. They are highly compartmentalized cells and therefore a finely tuned mitochondrial network constantly adapting to the local requirements is necessary. For neuronal maintenance, old or damaged mitochondria need to be degraded, while the functional mitochondrial pool needs to be replenished with freshly synthesized components. Mitochondrial biogenesis is known to be primarily regulated via the PGC-1α-NRF1/2-TFAM pathway at the transcriptional level. However, while transcriptional regulation of mitochondrial genes can change the global mitochondrial content in neurons, it does not explain how a morphologically complex cell such as a neuron adapts to local differences in mitochondrial demand. In this review, we discuss regulatory mechanisms controlling mitochondrial biogenesis thereby making a case for differential regulation at the transcriptional and translational level. In neurons, additional regulation can occur due to the axonal localization of mRNAs encoding mitochondrial proteins. Hitchhiking of mRNAs on organelles including mitochondria as well as contact site formation between mitochondria and endolysosomes are required for local mitochondrial biogenesis in axons linking defects in any of these organelles to the mitochondrial dysfunction seen in various neurological disorders.
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Affiliation(s)
- Jara Tabitha Hees
- TUM Medical Graduate Center, Technical University of Munich, 81675 Munich, Germany
- Max Planck Institute for Biological Intelligence, in Foundation, 82152 Planegg-Martinsried, Germany
| | - Angelika Bettina Harbauer
- Max Planck Institute for Biological Intelligence, in Foundation, 82152 Planegg-Martinsried, Germany
- Institute of Neuronal Cell Biology, Technical University of Munich, 80802 Munich, Germany
- Munich Cluster for Systems Neurology, 81377 Munich, Germany
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40
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The solution structure of Dead End bound to AU-rich RNA reveals an unusual mode of tandem RRM-RNA recognition required for mRNA regulation. Nat Commun 2022; 13:5892. [PMID: 36202814 PMCID: PMC9537309 DOI: 10.1038/s41467-022-33552-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 09/22/2022] [Indexed: 11/08/2022] Open
Abstract
Dead End (DND1) is an RNA-binding protein essential for germline development through its role in post-transcriptional gene regulation. The molecular mechanisms behind selection and regulation of its targets are unknown. Here, we present the solution structure of DND1's tandem RNA Recognition Motifs (RRMs) bound to AU-rich RNA. The structure reveals how an NYAYUNN element is specifically recognized, reconciling seemingly contradictory sequence motifs discovered in recent genome-wide studies. RRM1 acts as a main binding platform, including atypical extensions to the canonical RRM fold. RRM2 acts cooperatively with RRM1, capping the RNA using an unusual binding pocket, leading to an unusual mode of tandem RRM-RNA recognition. We show that the consensus motif is sufficient to mediate upregulation of a reporter gene in human cells and that this process depends not only on RNA binding by the RRMs, but also on DND1's double-stranded RNA binding domain (dsRBD), which is dispensable for binding of a subset of targets in cellulo. Our results point to a model where DND1 target selection is mediated by a non-canonical mode of AU-rich RNA recognition by the tandem RRMs and a role for the dsRBD in the recruitment of effector complexes responsible for target regulation.
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41
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Wang L, Zhan G, Maimaitiyiming Y, Su Y, Lin S, Liu J, Su K, Lin J, Shen S, He W, Wang F, Chen J, Sun S, Xue Y, Gu J, Chen X, Zhang J, Zhang L, Wang Q, Chang KJ, Chiou SH, Björklund M, Naranmandura H, Cheng X, Hsu CH. m6A modification confers thermal vulnerability to HPV E7 oncotranscripts via reverse regulation of its reader protein IGF2BP1 upon heat stress. Cell Rep 2022; 41:111546. [DOI: 10.1016/j.celrep.2022.111546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 07/20/2022] [Accepted: 09/29/2022] [Indexed: 11/03/2022] Open
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42
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Zhai D, Wang W, Ye Z, Xue K, Chen G, Hu S, Yan Z, Guo Y, Wang F, Li X, Xiang A, Li X, Lu Z, Wang L. QKI degradation in macrophage by RNF6 protects mice from MRSA infection via enhancing PI3K p110β dependent autophagy. Cell Biosci 2022; 12:154. [PMID: 36088389 PMCID: PMC9464412 DOI: 10.1186/s13578-022-00865-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 08/01/2022] [Indexed: 11/10/2022] Open
Abstract
Background Sepsis is a fatal condition commonly caused by Methicillin-resistant Staphylococcus aureus (MRSA) with a high death rate. Macrophages can protect the host from various microbial pathogens by recognizing and eliminating them. Earlier we found that Quaking (QKI), an RNA binding protein (RBP), was involved in differentiation and polarization of macrophages. However, the role of QKI in sepsis caused by pathogenic microbes, specifically MRSA, is unclear. This study aimed to investigate the role of QKI in regulation of host–pathogen interaction in MRSA-induced sepsis and explored the underlying mechanisms. Methods Transmission electron microscope and immunofluorescence were used to observe the autophagy level in macrophages. Real-time PCR and western blot were used to analyzed the expression of mRNA and protein respectively. The potential protein interaction was analyzed by iTRAQ mass spectrometry and Immunoprecipitation. RNA fluorescence in situ hybridization, dual-luciferase reporter assay and RNA immunoprecipitation were used to explore the mechanism of QKI regulating mRNA of PI3K-p110β. Results The mRNA level of QKI was aberrantly decreased in monocytes and PBMCs of septic patients with the increasing level of plasma procalcitonin (PCT). Then the mice with myeloid specific knockout of QKI was challenged with MRSA or Cecal Ligation and Puncture (CLP). Mice in these two models displayed higher survival rates and lower bacterial loads. Mechanistically, QKI deletion promoted phagocytosis and autophagic degradation of MRSA via activating p110β (a member of Class IA phosphoinositide 3-kinases) mediated autophagic response. QKI expression in macrophages led to the sequestration of p110β in mRNA processing (P) bodies and translational repression. Upon infection, the direct interaction of RNF6, a RING-type E3 ligase, mediated QKI ubiquitination degradation and facilitated PI3K-p110β related autophagic removal of pathogen. The administration of nanoparticles with QKI specific siRNA significantly protected mice from MRSA infection. Conclusions This study disclosed the novel function of QKI in the P body mRNA regulation during infection. QKI degradation in macrophage by RNF6 protects mice from MRSA infection via enhancing PI3K-p110β dependent autophagy. It suggested that QKI may serve as a potential theranostic marker in MRSA-induced sepsis. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13578-022-00865-9.
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43
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Courvan MCS, Niederer RO, Vock IW, Kiefer L, Gilbert WV, Simon MD. Internally controlled RNA sequencing comparisons using nucleoside recoding chemistry. Nucleic Acids Res 2022; 50:e110. [PMID: 36018791 PMCID: PMC9638901 DOI: 10.1093/nar/gkac693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 08/23/2022] [Indexed: 11/30/2022] Open
Abstract
Quantitative comparisons of RNA levels from different samples can lead to new biological understanding if they are able to distinguish biological variation from variable sample preparation. These challenges are pronounced in comparisons that require complex biochemical manipulations (e.g. isolating polysomes to study translation). Here, we present Transcript Regulation Identified by Labeling with Nucleoside Analogues in Cell Culture (TILAC), an internally controlled approach for quantitative comparisons of RNA content. TILAC uses two metabolic labels, 4-thiouridine (s4U) and 6-thioguanosine (s6G), to differentially label RNAs in cells, allowing experimental and control samples to be pooled prior to downstream biochemical manipulations. TILAC leverages nucleoside recoding chemistry to generate characteristic sequencing signatures for each label and uses statistical modeling to compare the abundance of RNA transcripts between samples. We verified the performance of TILAC in transcriptome-scale experiments involving RNA polymerase II inhibition and heat shock. We then applied TILAC to quantify changes in mRNA association with actively translating ribosomes during sodium arsenite stress and discovered a set of transcripts that are translationally upregulated, including MCM2 and DDX5. TILAC is broadly applicable to uncover differences between samples leading to improved biological insights.
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Affiliation(s)
- Meaghan C S Courvan
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06536, USA.,Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT06477, USA
| | - Rachel O Niederer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06536, USA
| | - Isaac W Vock
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06536, USA.,Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT06477, USA
| | - Lea Kiefer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06536, USA.,Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT06477, USA
| | - Wendy V Gilbert
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06536, USA
| | - Matthew D Simon
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06536, USA.,Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT06477, USA
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44
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Glauninger H, Wong Hickernell CJ, Bard JAM, Drummond DA. Stressful steps: Progress and challenges in understanding stress-induced mRNA condensation and accumulation in stress granules. Mol Cell 2022; 82:2544-2556. [PMID: 35662398 PMCID: PMC9308734 DOI: 10.1016/j.molcel.2022.05.014] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 03/14/2022] [Accepted: 05/11/2022] [Indexed: 01/11/2023]
Abstract
Stress-induced condensation of mRNA and protein into massive cytosolic clusters is conserved across eukaryotes. Known as stress granules when visible by imaging, these structures remarkably have no broadly accepted biological function, mechanism of formation or dispersal, or even molecular composition. As part of a larger surge of interest in biomolecular condensation, studies of stress granules and related RNA/protein condensates have increasingly probed the biochemical underpinnings of condensation. Here, we review open questions and recent advances, including the stages from initial condensate formation to accumulation in mature stress granules, mechanisms by which stress-induced condensates form and dissolve, and surprising twists in understanding the RNA components of stress granules and their role in condensation. We outline grand challenges in understanding stress-induced RNA condensation, centering on the unique and substantial barriers in the molecular study of cellular structures, such as stress granules, for which no biological function has been firmly established.
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Affiliation(s)
- Hendrik Glauninger
- Department of Biochemistry & Molecular Biology, University of Chicago, Chicago, IL 60673, USA
| | | | - Jared A M Bard
- Department of Biochemistry & Molecular Biology, University of Chicago, Chicago, IL 60673, USA
| | - D Allan Drummond
- Department of Biochemistry & Molecular Biology, University of Chicago, Chicago, IL 60673, USA.
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45
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West DL, Loughlin FE, Rivero-Rodríguez F, Vankadari N, Velázquez-Cruz A, Corrales-Guerrero L, Díaz-Moreno I, Wilce JA. Regulation of TIA-1 Condensates: Zn2+ and RGG Motifs Promote Nucleic Acid Driven LLPS and Inhibit Irreversible Aggregation. Front Mol Biosci 2022; 9:960806. [PMID: 35911965 PMCID: PMC9329571 DOI: 10.3389/fmolb.2022.960806] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 06/24/2022] [Indexed: 11/13/2022] Open
Abstract
Stress granules are non-membrane bound RNA-protein granules essential for survival during acute cellular stress. TIA-1 is a key protein in the formation of stress granules that undergoes liquid-liquid phase separation by association with specific RNAs and protein-protein interactions. However, the fundamental properties of the TIA-1 protein that enable phase-separation also render TIA-1 susceptible to the formation of irreversible fibrillar aggregates. Despite this, within physiological stress granules, TIA-1 is not present as fibrils, pointing to additional factors within the cell that prevent TIA-1 aggregation. Here we show that heterotypic interactions with stress granule co-factors Zn2+ and RGG-rich regions from FUS each act together with nucleic acid to induce the liquid-liquid phase separation of TIA-1. In contrast, these co-factors do not enhance nucleic acid induced fibril formation of TIA-1, but rather robustly inhibit the process. NMR titration experiments revealed specific interactions between Zn2+ and H94 and H96 in RRM2 of TIA-1. Strikingly, this interaction promotes multimerization of TIA-1 independently of the prion-like domain. Thus, through different molecular mechanisms, these stress granule co-factors promote TIA-1 liquid-liquid phase separation and suppress fibrillar aggregates, potentially contributing to the dynamic nature of stress granules and the cellular protection that they provide.
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Affiliation(s)
- Danella L. West
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - Fionna E. Loughlin
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | | | - Naveen Vankadari
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | | | | | - Irene Díaz-Moreno
- Institute for Chemical Research, University of Seville—CSIC, Seville, Spain
- *Correspondence: Irene Díaz-Moreno, ; Jacqueline A. Wilce,
| | - Jacqueline A. Wilce
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
- *Correspondence: Irene Díaz-Moreno, ; Jacqueline A. Wilce,
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46
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Brothers WR, Fakim H, Kajjo S, Fabian MR. P-bodies directly regulate MARF1-mediated mRNA decay in human cells. Nucleic Acids Res 2022; 50:7623-7636. [PMID: 35801873 PMCID: PMC9303261 DOI: 10.1093/nar/gkac557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 06/10/2022] [Accepted: 06/15/2022] [Indexed: 11/12/2022] Open
Abstract
Processing bodies (P-bodies) are ribonucleoprotein granules that contain mRNAs, RNA-binding proteins and effectors of mRNA turnover. While P-bodies have been reported to contain translationally repressed mRNAs, a causative role for P-bodies in regulating mRNA decay has yet to be established. Enhancer of decapping protein 4 (EDC4) is a core P-body component that interacts with multiple mRNA decay factors, including the mRNA decapping (DCP2) and decay (XRN1) enzymes. EDC4 also associates with the RNA endonuclease MARF1, an interaction that antagonizes the decay of MARF1-targeted mRNAs. How EDC4 interacts with MARF1 and how it represses MARF1 activity is unclear. In this study, we show that human MARF1 and XRN1 interact with EDC4 using analogous conserved short linear motifs in a mutually exclusive manner. While the EDC4–MARF1 interaction is required for EDC4 to inhibit MARF1 activity, our data indicate that the interaction with EDC4 alone is not sufficient. Importantly, we show that P-body architecture plays a critical role in antagonizing MARF1-mediated mRNA decay. Taken together, our study suggests that P-bodies can directly regulate mRNA turnover by sequestering an mRNA decay enzyme and preventing it from interfacing with and degrading targeted mRNAs.
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Affiliation(s)
- William R Brothers
- Lady David Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, H3T 1E2, Canada
| | - Hana Fakim
- Lady David Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, H3T 1E2, Canada
| | - Sam Kajjo
- Lady David Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, H3T 1E2, Canada
| | - Marc R Fabian
- Lady David Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, H3T 1E2, Canada.,Department of Biochemistry, McGill University Montreal, Quebec, H3A 1A3, Canada.,Gerald Bronfman Department of Oncology, McGill University Montreal, Quebec, H3A 1G5, Canada
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47
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Pérez-Ortín JE, Chávez S. Nucleo-cytoplasmic shuttling of RNA-binding factors: mRNA buffering and beyond. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2022; 1865:194849. [PMID: 35907432 DOI: 10.1016/j.bbagrm.2022.194849] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/18/2022] [Accepted: 07/23/2022] [Indexed: 06/15/2023]
Abstract
Gene expression is a highly regulated process that adapts RNAs and proteins content to the cellular context. Under steady-state conditions, mRNA homeostasis is robustly maintained by tight controls that act on both nuclear transcription and cytoplasmic mRNA stability. In recent years, it has been revealed that several RNA-binding proteins (RBPs) that perform functions in mRNA decay can move to the nucleus and regulate transcription. The RBPs involved in transcription can also travel to the cytoplasm and regulate mRNA degradation and/or translation. The multifaceted functions of these shuttling nucleo-cytoplasm RBPs have raised the possibility that they can act as mRNA metabolism coordinators. In addition, this indicates the existence of crosstalk mechanisms between the enzymatic machineries that drive the different mRNA life-cycle phases. The buffering of the mRNA concentration is the best known consequence of a transcription-degradation crosstalk counteraction, but alternative ways of RBP action can also imply enhanced gene regulation.
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Affiliation(s)
- José E Pérez-Ortín
- Instituto de Biotecnología y Biomedicina (Biotecmed), Facultad de Biológicas, Universitat de València. C/Dr. Moliner 50, E46100 Burjassot, Spain.
| | - Sebastián Chávez
- Departamento de Genética, Universidad de Sevilla and Instituto de Biomedicina de Sevilla (IBiS), Hospital Virgen del Rocío-CSIC-Universidad de Sevilla, 41013 Seville, Spain; Dirección de Evaluación y Acreditación, Agencia Andaluza del Conocimiento, Doña Berenguela s/n, planta 3ª C.P., 14006 Córdoba, Spain
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48
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Rodriguez W, Muller M. Shiftless, a Critical Piece of the Innate Immune Response to Viral Infection. Viruses 2022; 14:v14061338. [PMID: 35746809 PMCID: PMC9230503 DOI: 10.3390/v14061338] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/08/2022] [Accepted: 06/16/2022] [Indexed: 12/14/2022] Open
Abstract
Since its initial characterization in 2016, the interferon stimulated gene Shiftless (SHFL) has proven to be a critical piece of the innate immune response to viral infection. SHFL expression stringently restricts the replication of multiple DNA, RNA, and retroviruses with an extraordinary diversity of mechanisms that differ from one virus to the next. These inhibitory strategies include the negative regulation of viral RNA stability, translation, and even the manipulation of RNA granule formation during viral infection. Even more surprisingly, SHFL is the first human protein found to directly inhibit the activity of the -1 programmed ribosomal frameshift, a translation recoding strategy utilized across nearly all domains of life and several human viruses. Recent literature has shown that SHFL expression also significantly impacts viral pathogenesis in mouse models, highlighting its in vivo efficacy. To help reconcile the many mechanisms by which SHFL restricts viral replication, we provide here a comprehensive review of this complex ISG, its influence over viral RNA fate, and the implications of its functions on the virus-host arms race for control of the cell.
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49
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Ehses J, Schlegel M, Schröger L, Schieweck R, Derdak S, Bilban M, Bauer K, Harner M, Kiebler MA. The dsRBP Staufen2 governs RNP assembly of neuronal Argonaute proteins. Nucleic Acids Res 2022; 50:7034-7047. [PMID: 35687120 PMCID: PMC9262589 DOI: 10.1093/nar/gkac487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 05/10/2022] [Accepted: 05/26/2022] [Indexed: 12/24/2022] Open
Abstract
Mature microRNAs are bound by a member of the Argonaute (Ago1-4) protein family, forming the core of the RNA-induced silencing complex (RISC). Association of RISC with target mRNAs results in ribonucleoprotein (RNP) assembly involved in translational silencing or RNA degradation. Yet, the dynamics of RNP assembly and its underlying functional implications are unknown. Here, we have characterized the role of the RNA-binding protein Staufen2, a candidate Ago interactor, in RNP assembly. Staufen2 depletion resulted in the upregulation of Ago1/2 and the RISC effector proteins Ddx6 and Dcp1a. This upregulation was accompanied by the displacement of Ago1/2 from processing bodies, large RNPs implicated in RNA storage, and subsequent association of Ago2 with polysomes. In parallel, Staufen2 deficiency decreased global translation and increased dendritic branching. As the observed phenotypes can be rescued by Ago1/2 knockdown, we propose a working model in which both Staufen2 and Ago proteins depend on each other and contribute to neuronal homeostasis.
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Affiliation(s)
- Janina Ehses
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Melina Schlegel
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Luise Schröger
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Rico Schieweck
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Sophia Derdak
- Core Facilities, Medical University of Vienna, 1090 Vienna, Austria
| | - Martin Bilban
- Department of Laboratory Medicine and Core Facility Genomics, Medical University, of Vienna, 1090 Vienna, Austria
| | - Karl Bauer
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Max Harner
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Michael A Kiebler
- To whom correspondence should be addressed. Tel: +49 89 2180 75884; Fax: +49 89 2180 75885;
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50
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Domanski M, Dedic E, Pérez ME, Cléry A, Campagne S, Uldry AC, Braga S, Heller M, Rabl J, Afanasyev P, Boehringer D, Nováček J, Allain FT, Mühlemann O. 40S hnRNP particles are a novel class of nuclear biomolecular condensates. Nucleic Acids Res 2022; 50:6300-6312. [PMID: 35687109 PMCID: PMC9226511 DOI: 10.1093/nar/gkac457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/12/2022] [Accepted: 05/16/2022] [Indexed: 11/17/2022] Open
Abstract
Heterogenous nuclear ribonucleoproteins (hnRNPs) are abundant proteins implicated in various steps of RNA processing that assemble on nuclear RNA into larger complexes termed 40S hnRNP particles. Despite their initial discovery 55 years ago, our understanding of these intriguing macromolecular assemblies remains limited. Here, we report the biochemical purification of native 40S hnRNP particles and the determination of their complete protein composition by label-free quantitative mass spectrometry, identifying A-group and C-group hnRNPs as the major protein constituents. Isolated 40S hnRNP particles dissociate upon RNA digestion and can be reconstituted in vitro on defined RNAs in the presence of the individual protein components, demonstrating a scaffolding role for RNA in nucleating particle formation. Finally, we revealed their nanometer scale, condensate-like nature, promoted by intrinsically disordered regions of A-group hnRNPs. Collectively, we identify nuclear 40S hnRNP particles as novel dynamic biomolecular condensates.
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Affiliation(s)
- Michal Domanski
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Emil Dedic
- Institute of Biochemistry, Department of Biology, ETH Zürich, Hönggerbergring 64, 8093 Zürich, Switzerland
| | - Maria Escura Pérez
- Institute of Biochemistry, Department of Biology, ETH Zürich, Hönggerbergring 64, 8093 Zürich, Switzerland
| | - Antoine Cléry
- Institute of Biochemistry, Department of Biology, ETH Zürich, Hönggerbergring 64, 8093 Zürich, Switzerland
| | - Sébastien Campagne
- Institute of Biochemistry, Department of Biology, ETH Zürich, Hönggerbergring 64, 8093 Zürich, Switzerland
| | - Anne-Christine Uldry
- Proteomics & Mass Spectrometry Core Facility, Department for BioMedical Research (DBMR), University of Bern, Murtenstrasse 28, 3008 Bern, Switzerland
| | - Sophie Braga
- Proteomics & Mass Spectrometry Core Facility, Department for BioMedical Research (DBMR), University of Bern, Murtenstrasse 28, 3008 Bern, Switzerland
| | - Manfred Heller
- Proteomics & Mass Spectrometry Core Facility, Department for BioMedical Research (DBMR), University of Bern, Murtenstrasse 28, 3008 Bern, Switzerland
| | - Julius Rabl
- Cryo-EM Knowledge Hub, ScopeM, Otto Stern Weg 3, ETH Zürich, 8093 Zürich, Switzerland
| | - Pavel Afanasyev
- Cryo-EM Knowledge Hub, ScopeM, Otto Stern Weg 3, ETH Zürich, 8093 Zürich, Switzerland
| | - Daniel Boehringer
- Cryo-EM Knowledge Hub, ScopeM, Otto Stern Weg 3, ETH Zürich, 8093 Zürich, Switzerland
| | - Jiří Nováček
- Cryo-Electron Microscopy and Tomography Core Facility, Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Frédéric T Allain
- Institute of Biochemistry, Department of Biology, ETH Zürich, Hönggerbergring 64, 8093 Zürich, Switzerland
| | - Oliver Mühlemann
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
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